# CVE-2026-15075: Eclipse Vert.x sensitive header propagation in HttpClient redirect handler

Source: https://junglewise.ai/threats/cve-2026-15075-eclipse-vert-x-sensitive-header-propagation-in-httpclient  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-14. Updated: 2026-07-14  
License: CC BY 4.0 with a link back

CVE-2026-15075 · Severity: info · CVSS 8.2 · Published 2026-07-14

Eclipse Vert.x is a toolkit for building reactive applications on the Java Virtual Machine. A security flaw in its HTTP client component allows sensitive information, such as login credentials, session cookies, and API keys, to be accidentally sent to untrusted third-party servers during a web redirect. An attacker could exploit this to steal user credentials or access tokens by tricking the application into requesting a malicious URL.

Vendors: [Eclipse Foundation](https://junglewise.ai/threats/vendors/eclipse-foundation).

## Quick answers

**Is CVE-2026-15075 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-15075 being exploited in the wild.

**How severe is CVE-2026-15075?** Informational severity, with a CVSS score of 8.2, published 14 July 2026.

**Which products and versions are affected?** Eclipse Foundation Vert.x <= 4.5.29, <= 5.1.4.

**Is there a fix for CVE-2026-15075?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-15075 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-15075?** Check whether you run Eclipse Foundation Vert.x at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A vulnerability exists in the DefaultRedirectHandler of vertx-core where request headers are propagated as-is during cross-origin HTTP 30x redirects. The handler fails to perform origin comparison (scheme, host, port) before copying headers, only stripping the Content-Length header. Consequently, sensitive headers such as Authorization, Cookie, Proxy-Authorization, and custom tokens (e.g., X-API-Token) are forwarded to the redirect target. An attacker can exploit this by providing a URL to a component that uses HttpClient (like a webhook or proxy) that redirects to an attacker-controlled server to capture these credentials. The issue affects versions up to 4.5.29 and 5.1.4.

## Affected products

- Eclipse Foundation Eclipse Vert.x <= 4.5.29, <= 5.1.4

## Timeline

- 2026-07-14: advisory: CVE-2026-15075 published by NVD and Eclipse Foundation

## References

- [https://gitlab.eclipse.org/security/cve-assignment/-/work_items/161](https://gitlab.eclipse.org/security/cve-assignment/-/work_items/161)

## Related threats

- [Eclipse Vert.x DoS via unbounded SNI SslContext cache growth](https://junglewise.ai/threats/cve-2026-6860-eclipse-vert-x-dos-via-unbounded-sni-sslcontext-cache-growth)